Inca de Oro

Porphyry copper (Cu-Mo) deposit in Atacama, Chile

Names and other identifiers

GMRAP ID 302
Alternate names Cerro La Campana, Cerro Bonete, Desierto, Dina, Edita, Juana, Punta de Lobos
Tract name Chile-Peru Paleocene–Eocene Toquepala (005pCu1008)
Site status deposit

Geographic location

Country Chile
State or province Atacama
Geographic location -69.871388889, -26.766111111
Geologic map unit -69.871388889, -26.766111111
Nearby data

Geologic information

Deposit type Porphyry copper
Deposit subtype Cu-Mo
Age (Ma) 63Ma
Age determination method unknown
Age range 66–60 Ma
Age reference Singer and others (2008)
Minerals adularia, alunite, argentite, arsenopyrite, azurite/malachite, barite, bismuthinite, brochantite, chalcocite, chalcopyrite, chlorite, copper, cuprite, dioptase, chrysocolla, cinnabar, electrum, enargite, galena, gold, hematite, jarosite, kaolinite, lindgrenite [Cu3(MoO4)2(OH)2], molybdenite, powellite, pyrite, sericite, szenicsite [Cu3MoO4(OH)4], tourmaline
Associated rocks breccia, granodiorite, carbonate rock, diorite, andesite
Tectonic setting continental margin
Stratigraphic age Paleocene

Commodity and development information

Development status Past Producer
Major commodities Cu, Au, Mo, Ag
Tonnage (Mt) 460Mt
Cu grade (%) 0.409%
Mo grade (%) 0.063%
Au grade (g/t) 0.104g/t
Ag grade (g/t) 1.623g/t
Contained copper 1,880,000t
Gold-Moly ratio 1.6

Reference information

Comments Cu enrichment age (K–Ar, alunite) 14 Ma. Updated location from company reports. Total measured, indicated, and inferred resources as of June 30, 2012. Feasability for 2014 startup as open pit.
Study area name Andes
References Colley and others (1989); Francis and others (1996); Palacios and others (1992); Sillitoe and McKee (1996); Singer and others (2008); PanAust (2014)
Site reference Cunningham and others (2008)
Colley, H., Treloar, P.J., and Diaz, F., 1989, Gold-silver mineralization in the El Salvador region, northern Chile, in Keays, R.R., Ramsay, W.R.H., and Groves, D.I., eds., The geology of gold deposits—The perspective in 1988: Economic Geology Monograph 6, p. 208–217.
Francis, C.A., Pitman, L.C., and Lange, D.E., 1996, A new copper molybdate from Inca de Oro, Atacama, Chile: Mineralogical Record, v. 28, p. 387–394.
Palacios C.M., Lahsen, A.A., and Sylvester, H., 1992, Low-sulfur epithermal gold mineralization at Inca de Oro, northern Chile—Mineralogy and fluid inclusions: Journal of South American Earth Sciences, v. 6, no. 3, p. 183–189.
PanAust, 2014, The Inca de Oro copper-gold project and Carmen deposit, Chile: PanAust Web page, accessed June 16, 2014, at http://www.panaust.com.au/sites/default/files/05_IncaDeOro.pdf.Sillitoe, R.H., and McKee, E.H., 1996, Age of supergene oxidation and enrichment in the Chilean porphyry copper province: Economic Geology, v. 91, p. 164–179. (Also available at http://dx.doi.org/10.2113/gsecongeo.91.1.164.)Singer, D.A., Berger, V.I., and Moring, B.C., 2008, Porphyry copper deposits of the world—Database and grade and tonnage models, 2008: U.S. Geological Survey Open-File Report 2008-1155, [45] p. and digital data, accessed December 31, 2013, at http://pubs.usgs.gov/of/2008/1155/.